Quercetin induces MGMT+ glioblastoma cells apoptosis via dual inhibition of Wnt3a/ß-Catenin and Akt/NF-κB signaling pathways.

BACKGROUND: Surgical resection combined with radiotherapy and chemotherapy remains a common clinical treatment for glioblastoma multiforme (GBM). However, the therapeutic outcomes have not been satisfying due to drug resistance and other factors. Quercetin, a phytoingredient capable of crossing the blood-brain barrier, has shown effectiveness in the treatment of various solid tumors. Nevertheless, the potential of quercetin in GBM treatment has not been adequately explored. PURPOSE: This study aims to investigate the effects and mechanisms of quercetin on MGMT+GBM cells. METHODS: The potential targets and mechanisms of quercetin in glioma treatment were predicted based on network pharmacology and molecular docking. The effects of quercetin on cell inhibition rate, cell migration ability, cell cycle arrest, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), Mitochondrial superoxide formation and apoptosis were measured by the CCK8 assay, wound healing assay, PI/RNase staining, JC-1 assay, DCFH-DA assay, MitoSOX staining and Annexin V-FITC/PI double staining, respectively. The methylation status of the MGMT promoter was assessed through methylation-specific polymerase chain reaction (MS-PCR). DNA damage was quantified by alkaline/neutral comet assay and TUNEL assay. The intracellular localization and expression of NF-κB and MGMT were revealed by immunofluorescence. The expression of migration-related proteins, matrix metalloproteinases, apoptosis-related proteins, cyclins, DNA damage/repair enzymes and related pathway proteins was detected by Western blot. RESULTS: Network pharmacology identified 96 targets and potential molecular mechanisms of quercetin in glioma treatment. Subsequent experiments confirmed the synergistic effect of quercetin in combination with temozolomide (TMZ) on T98G cells. Quercetin significantly suppressed the growth and migration of human GBM T98G cells, induced apoptosis, and arrested cells in the S-phase cell cycle. The collapse of mitochondrial membrane potential, ROS generation, enhanced Bax/Bcl-2 ratio, and strengthened cleaved-Caspase 9 and cleaved-Caspase 3 suggested the involvement of ROS-mediated mitochondria-dependent apoptosis in the process of quercetin-induced apoptosis. In addition, quercetin-induced apoptosis was accompanied by intense DNA double-strand breaks (DSBs), γH2AX foci formation, methylation of MGMT promoter, increased cleaved-PARP, and reduced MGMT expression. Quercetin may influence the expression of the key DNA repair enzyme, MGMT, by dual suppression of the Wnt3a/ß-Catenin and the Akt/NF-κB signaling pathways, thereby promoting apoptosis. Inhibition of Wnt3a and Akt using specific inhibitors hindered MGMT expression. CONCLUSION: Our study provides the first evidence that quercetin may induce apoptosis in MGMT+GBM cells via dual inhibition of the Wnt3a/ß-Catenin pathway and the Akt/NF-κB signaling pathway. These findings suggest that quercetin could be a novel agent for improving GBM treatment, especially in TMZ-resistant GBM with high MGMT expression.

Resveratrol Relieves Gouty Arthritis by Promoting Mitophagy to Inhibit Activation of NLRP3 Inflammasomes.

BACKGROUND: Gouty arthritis (GA) is a common inflammatory disease with pain caused by the deposition of monosodium urate (MSU) crystals into joints and surrounding tissues. Resveratrol (Res), derived from grapes and peanuts and the traditional Chinese medicine (TCM) Reynoutria japonica for GA, acts against oxidation and inflammation. The present study aimed to investigate the therapeutic effect and mechanism of Res on GA. METHODS: Arthritis rat models, MSU-induced peritonitis mouse models, and inflammatory models of mouse bone marrow-derived macrophage (BMDM) were used in this study. Enzyme-linked immunosorbent assay (ELISA), JC-1, histopathological, immunofluorescence, flow cytometry, Western blot methods were applied to observe the effects of resveratrol on NLRP3 inflammasomes and mitophagy. RESULTS: Res significantly improves the gait score and synovitis of rats with GA and inhibits the peritoneal inflammation induced by MSU. Res inhibits the MSU-induced activation of NLRP3 inflammasomes by reducing the levels of IL-1ß, IL-18, and Caspase-1 and the pyroptosis of macrophages. In addition, Res raises the level of mitochondrial membrane potential, inhibits the expression of P62 and Pink1, enhances the expressions of LC3B-II, Parkin, and TOMM20, and promotes mitophagy, while mitophagy inhibitors reverse the inhibitory effect of Res on the activation of NLRP3 inflammasomes. CONCLUSION: Res significantly improves GA, and the underlying mechanism might be inhibiting the activation of NLRP3 inflammasomes by triggering the Pink1/Parkin pathway to promote mitophagy.

Zerumbone ameliorates behavioral impairments and neuropathology in transgenic APP/PS1 mice by suppressing MAPK signaling.

BACKGROUND: Alzheimer's disease (AD) is a major clinical problem, but there is a distinct lack of effective therapeutic drugs for this disease. We investigated the potential therapeutic effects of zerumbone, a subtropical ginger sesquiterpene, in transgenic APP/PS1 mice, rodent models of AD which exhibit cerebral amyloidosis and neuroinflammation. METHODS: The N9 microglial cell line and primary microglial cells were cultured to investigate the effects of zerumbone on microglia. APP/PS1 mice were treated with zerumbone, and non-cognitive and cognitive behavioral impairments were assessed and compared between the treatment and control groups. The animals were then sacrificed, and tissues were collected for further analysis. The potential therapeutic mechanism of zerumbone and the signaling pathways involved were also investigated by RT-PCR, western blot, nitric oxide detection, enzyme-linked immunosorbent assay, immunohistochemistry, immunofluorescence, and flow cytometry analysis. RESULTS: Zerumbone suppressed the expression of pro-inflammatory cytokines and induced a switch in microglial phenotype from the classic inflammatory phenotype to the alternative anti-inflammatory phenotype by inhibiting the mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B signaling pathway in vitro. After a treatment period of 20 days, zerumbone significantly ameliorated deficits in both non-cognitive and cognitive behaviors in transgenic APP/PS1 mice. Zerumbone significantly reduced ß-amyloid deposition and attenuated pro-inflammatory microglial activation in the cortex and hippocampus. Interestingly, zerumbone significantly increased the proportion of anti-inflammatory microglia among all activated microglia, potentially contributing to reduced ß-amyloid deposition by enhancing phagocytosis. Meanwhile, zerumbone also reduced the expression of key molecules of the MAPK pathway, such as p38 and extracellular signal-regulated kinase. CONCLUSIONS: Overall, zerumbone effectively ameliorated behavioral impairments, attenuated neuroinflammation, and reduced ß-amyloid deposition in transgenic APP/PS1 mice. Zerumbone exhibited substantial anti-inflammatory activity in microglial cells and induced a phenotypic switch in microglia from the pro-inflammatory phenotype to the anti-inflammatory phenotype by inhibiting the MAPK signaling pathway, which may play an important role in its neuroprotective effects. Our results suggest that zerumbone is a potential therapeutic agent for human neuroinflammatory and neurodegenerative diseases, in particular AD.

[The effect of the type II collagen protein from Zaocys on cytokines production by synoviocytes in rats with adjuvant arthritis].

OBJECTIVE: To investigate the effect of the type II collagen (C II) protein from Zaocys on cytokines production by synoviocytes in rats with adjuvant arthritis (AA). METHODS: Type II collagen protein was abstracted and purificated from Zaocys. Adjuvant arthritis (AA) was induced by a single intradermal injection of 0.1 mL of complete Freund's adjuvant into the left hind paw. Synoviocytes' supernatants were harvested and synoviocytes-Peyer's Patches (PP) cells coculture system were developed. Tumor necrosis factor-alpha (TNF-alpha) activity was measured by L929 cytotoxicity bioassay and Interleukin (IL)-1beta activity was measured by MTT dye reduction. The synoviocytes' supernatants cytokines' levels were detected by ELISA. RESULTS: Each concentration of C II from Zaocys had no effect on IL-1beta and TNF-alpha production by synoviocytes in vitro. Middle concentration of C II suppressed the activity of IL-1beta and TNF-alpha production by synoviocytes-PP cells coculture system (P < 0.05). Treating with low and high dose of C II suppressed the activity of TNF-alpha and IL-1beta producing by synoviocyte (P < 0.05), significantly suppressed in the group of AA rats treated with middle dose of C II (P < 0.01). Treating with middle and high dose of C II decreased the level of synoviocytes' supernatants TNF-alpha (P < 0.05), the level of synoviocytes' supernatants IL-1beta decreased in all treating groups (P < 0.05). Treating with middle dose of C II increased the level of serum TGF-beta (P < 0.05). Middle concentration of C II suppressed the activity of IL-1 and TNF production by synoviocytes-PP cells coculture system (P < 0.05). CONCLUSIONS: C II from Zaocys has no direct effect on the activity of IL-1beta and TNF production by synoviocytes in vitro. Oral administration of type II collagen protein from Zaocys can effectively suppressed the activity and level of the cytokines production by synoviocytes in rats with adjuvant arthritis (AA).

[Character of denitrifying phosphorus removal using MUCT process: operation at low C/N rate].

The effect of phosphorus uptake in the anaerobic zone of MUCT process fed with low C/N rate wastewater was studied. The experimental results shows that: (1) Because of the concentration of the COD is relative higher, nitrate is firstly used by the traditional denitrifying bacteria in the cycle sludge, and can not act as the electron acceptor for DPB. So the main action in the first anaerobic zone is phosphate release; (2) The DPB utilizes the PHB as the carbon stored in the anaerobic zone, and nitrate as electron acceptor to uptake phosphorus and the amount increases daily from 0.93 mg/L to 18 mg/L, and the anaerobic phosphorus rate stabilizes to 40 percent finally in the second anaerobic zone; (3) The ineffective phosphorus release process occurs in the third anaerobic zone because the lower nitrate and COD concentration,and phosphate release amount is from 0.27 to 3 mg/L; (4) The COD, TN, TP removal rates are higher and the TP and TN concentration in effluent is below 10 mg/L and 0.9 mg/L respectively.